No input field for Apple ID Verification Code

I have an older iPad Mini and when I try and use a game iOS Game Center asks for my password, which I enter, and is accepted. Then it asks to type in the Apple ID Verification Code, although there is nowhere to type it in.

EDIT: Thanks to fsb's suggestion the verification code was accepted by typing it directly after the password into the Game Center login password field. I'm shocked Apple would expect anyone to know to do this without prior knowledge!

Solution 1:

According to this Apple Support page, the issue is two-factor authentication with older devices/iOS.

What if I use two-factor authentication on a device running older software?

If you use two-factor authentication with devices running older OS versions, you might be asked to add your six-digit verification code to the end of your password when signing in.

Get your verification code from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field without any spaces between the password and the verification code.